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UNIS/INF/398
28 February 2011

New Report on Health Effects due to Radiation from the Chernobyl Accident

VIENNA, 28 February (UN Information Service) - Despite new research data becoming available, the major conclusions regarding the scale and nature of the health consequences of the 1986 Chernobyl accident are "essentially consistent" with previous assessments", the United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR) says in a report released today.

Although another 19 ARS survivors had died by 2006, those deaths had different causes not usually associated with radiation exposure, the report said

Skin injuries and radiation-related cataracts were among the most common consequences in ARS survivors

Although several hundred thousand people, as well as the emergency workers, were involved in recovery operations, there is no consistent evidence of health effects that can be
attributed to radiation exposure, apart from indications of increased incidence of leukemia and of cataracts among those who received higher doses.

All the ARS survivors are under clinical surveillance at hospitals in Moscow, or Kiev. "Most suffered functional sexual disorders up to 1996; however, 14 normal children were born to survivor families within the first five years of the accident," said the report.

Regarding the general public in the three most affected countries, the only evidence of health effects due to radiation is an increase in thyroid cancer among people exposed as children or adolescents in 1986. There were more than 6,000 cases reported from 1991 to 2005 in Belarus, Ukraine and four most affected regions in the Russian Federation. By 2005, 15 of the cases had proven fatal, the report said. A "substantial portion" of the cases could be attributed to drinking milk in 1986 contaminated with short-lived iodine-131 from the accident.

Otherwise the report reconfirmed that radiation doses to the general public in the three most affected countries were relatively low and most residents "need not live in fear of serious health consequences". In the areas of Belarus, the Russian Federation and Ukraine defined as "contaminated areas" by the former Soviet Union, because of higher soil levels of the long-lived caesium-137, the average additional dose over the period 1986-2005 is "approximately equivalent to that from a medical computed tomography scan". The report said that the severe disruption caused by the accident resulted in "major social and economic impact and great distress for the affected populations".

The report also says that it is not possible to state scientifically that radiation caused a particular cancer in an individual. "This means that in terms of specific individuals, it is impossible to determine whether their cancers are due to the effects of radiation or to other causes, or moreover, whether they are due to the accident or background radiation."

And because of "unacceptable uncertainties in the predictions," the Committee decided not to use models to project absolute numbers of effects in populations exposed to low doses, the report said.

The report is UNSCEAR's third to study the accident, which occurred on 26 April 1986. It was prepared in close cooperation with scientists from Belarus, Russian Federation and Ukraine, who worked with the Committee to scrutinize relevant information. Dose estimates have been extended to over 500,000 workers involved in the recovery after the accident, from 380,000. The estimation of thyroid doses has been expanded to include 100 million people in Belarus, the Russian Federation and Ukraine from five million.

It is one of three scientific annexes to be released as part of the second volume of supporting evidence underpinning the Committee's 2008 report to the General Assembly. Its publication has been delayed. The other two annexes, about radiation exposures in numerous smaller-scale accidents and on radiation effects on non-human biota, will be released next month.

The mandate of UNSCEAR, established in 1955, is to undertake broad reviews of the sources of ionizing radiation and the effects on human health and the environment. Its assessments provide a scientific foundation for United Nations agencies and governments to formulate standards and programmes for protection against ionizing radiation.